“Any method of seeking the truth can also be used to plant a lie.” Therein lies the root of the brilliantly dangerous Allied plan (which MI5 called Double Cross)—recounted by Macintyre with the same skill and suspense he displayed in Operation Mincemeat and Agent Zigzag—to throw off the Germans and launch an assault at Normandy on June 6, 1944. The key to the plan—convincing Germany that the impending attack would come either at Pas de Calais or in Norway—was the careful manipulation of five double agents, each feeding misinformation back to their German handlers. Polish zealot Roman Czerniawski volunteered his services to his German captors, only to defect to Britain and become “Agent Brutus.” Serbian playboy Dusan Popov (“Agent Tricycle”) became one of MI5’s most prized assets. Failed Catalan chicken farmer Juan Pujol (“Agent Garbo”) badgered both German and British intelligence services into accepting him, eventually becoming the linchpin of the D-Day ploy. Lily Sergeyev (“Agent Treasure”), a high-strung Frenchwoman, had the opportunity to blow the whole operation with a single punctuation mark, while Elvira de la Fuente Chaudoir (“Agent Bronx”) transformed from a gambling Peruvian society girl to solid double agent. Macintyre effortlessly weaves the agents’ deliciously eccentric personalities with larger wartime events to shape a tale that reads like a top-notch spy thriller. Photos, map. Agent: Ed Victor, Ed Victor Ltd. (July)